I believe that intelligence leads to overanalysis and inaction. Some people call it "analysis paralysis". Call it whatever you want, it keeps me from getting things done. Looking back, all the time I spent planning and preparing for new ventures was basically wasted time. It's impossible to predict what will happen when you try something new. Better to just figure things out as you go.
"Recently I was lecturing to real estate agents on how to improve productivity." And they said, "Stop lecturing to us, Karen. You are a machine!"